Apparatus for selectively producing and testing fluids from a multiple zone well

ABSTRACT

APPARATUS FOR SELECTIVELY PRODUCING AND TESTING FLUIDS FROM A MULTIPLE ZONE WELL INCLUDING A PACKER SEALING OFF ONE OF THE ZONES ANOTHER AND A TUBING STRING IN FLUID COMMUNICATION WITH THE LOWER ZONE. A LOWER ZONE CROSS-OVER IS DISPOSED ABOVE THE PACKER IN FLUID COMMUNICATION WITH THE TUBING STRING FOR DIVERTING FLUIDS FROM THE LOWER ZONE AND INTO THE ANNULUS BETWEEN THE TUBING STRING AND THE WELL. AN UPPER ZONE FLUID INLET IS IN FLUID COMMINICATION WITH THE TUBING STRING ABOVE THE LOWER ZONE CROSS-OVER. A PUMP EXTENSION IS SELECTIVELY MOVABLE IN THE TUBING STRING BETWEEN A POSITION SEALING OFF THE TUBING STRING AT ONE POINT ABOVE THE LOWER ZONE CROSS-OVER AND BELOW THE UPPER ZONE FLUID INLET AND AT ANOTHER POINT BELOW BOTH THE LOWER ZONE CROSSOVER AND   THE UPPER ZONE FLUID INLET. THE PUMP EXTENSION INCLUDES A FIRST NORMALLY OPEN FLUID INLET FOR REMOVING FLUIDS FROM BOTH OF THE ZONES AND A SECOND NORMALLY CLOSED FLUID INLET FOR REMOVING FLUIDS FROM THE LOWER ZONE.

p 20, 1911 .A. LAMBIE 3,605,887

APPARATUS FOR SE TIVELY PRODUCING AND TESTING FLUIDS M A MULTIPLE ZONE WELL 19d May 21, 1970 Lal l 5 FIG 2 L 4 uni \J \J INVENTOR. DARRYL A. LAMBIE United States Patent APPARATUS FOR SELECTIVELY PRODUCING AND TESTING FLUIDS FROM A MULTIPLE ZONE WELL Darryl A. Lambie, Midland, Tex., assignor to Shell Oil Company, New York, N.Y. Filed May 21, 1970, Ser. No. 39,340 Int. Cl. E2lb 43/00 U.S. Cl. 166-105 7 Claims ABSTRACT OF THE DISCLOSURE Apparatus for selectively producing and testing fluids from a multiple zone well including a packer sealing off one of the zones from another and a tubing string in fluid communication with the lower zone. A lower zone cross-over is disposed above the packer in fluid communication with the tubing string for diverting fluids from the lower zone and into the annulus between the tubing string and the well. An upper zone fluid inlet is in fluid communication with the tubing string above the lower zone cross-over. A pump extension is selectively movable in the tubing string between a position sealing off the tubing string at one point above the lower zone cross-over and below the upper zone fluid inlet and at another point below both the lower zone crossover and the upper zone fluid inlet. The pump extension includes a first normally open fluid inlet for removing fluids from both of the zones and a second normally closed fluid inlet for removing fluids from the lower zone.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to well completion; and more particularly, to the selective production and testing of fluids normally produced from multiple zone wells.

Description of the prior art It is often desirable to produce fluids from a well borehole extending into a multiple zone within a subterranean earth formation. In such cases, confluent production of the zones will result in significant capital cost savings in artificial lift equipment and decreased operating costs. Confluent production from such multiple zones will eliminate the need for dual beam units, tandem pumping equipment, or lower zone gas vent strings. However, present equipment is not suitable for both providing confluent production from multiple zone and selective testing of such zones that may be necessary in order to monitor flood response therein.

SUMMARY OF THE INVENTION It is an object of this invention to provide apparatus for the confluent production of multiple zones traversed by a well borehole.

It is a further objection of this invention to provide apparatus for both the confluent production of multiple zones and the selective testing of the fluids produced from such zones.

These and other objects are preferably accomplished by installing both a packer in the well borehole sealing off one of the zones from another and a tubing string in fluid communication with the lower zone. A lower zone cross-over is disposed above the packer in fluid communication with the tubing string for diverting fluids from the lower zone and into the annulus between the tubing string and the well. An upper zone fluid inlet is in fluid communication with the tubing string above the lower zone cross-over. A pump extension is selectively movable in the tubing string between a position sealing off the tubing string at one point above the lower zonecross-over and below the upper zone fluid inlet and at another point below both the lower zone crossover and the upper zone fluid inlet. The pump extension includes a first normally open fluid inlet for removing fluids from both of the zones and a second normally closed fluid inlet for removing fluids from the lower zone. In this manner, by selectively moving the pump extension within the tubing string and opening and closing the fluid inlets therein, fluids may be both produced simultaneously from the multiple zones or selectively tested from each of the zones.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical sectional view, partly schematic, of apparatus for both producing and selectively testing fluids from multiple zones traversed by a well borehole;

FIG. 2 is a vertical schematic illustration of the testing of fluids produced from the upper zone of FIG. 1; and

FIG. 3 is a vertical schematic illustration of the testing of fluids produced from the lower zone of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, a well borehole 10 is shown wherein the well borehole 10 traverses an upper zone 11 and a lower zone 12 within a subterranean earth formation 13. It is to be understood that a plurality of such zones 11 and 12 may be disposed along well borehole 10, all of the zones containing formation fluids therein, which fluids are to be produced therefrom in the manner set forth hereinbelow.

Well borehole 10 may be cased, as at casing 14, along the extent of zones 11 and 12 with casing 14 cemented therein, as at cementing 15, all as is well known in the art.

A conventional retrievable or permanent packer 16 or the like is disposed in well borehole 10 in a manner sealing otf lower zone 12 from upper zone 11. Well borehole 10 is also perforated at locations therein providing fluid communication between borehole 10 and zones 11 and 12, as for example, at perforations 17 communicating with upper zone 11 and perforations 18 communicating with lower zone 12. It is is to be understood that such perforations may be formed by any means known in the art, as for example, by jet perforating means, and, although only two such perforations are shown, any number of perforations may be formed along the extents of zones 11 and 12.

A conventional tubing string 19 is disposed in well borehole 10, the upper end 20 extending out of well borehole 10 to conventional oil recovery equipment (not shown) at earth surface 21, and the lower end preferably includes a conventional on-off sealing connector 22 having a left-hand J-latch locking device thereon. In this manner, tension may be put on the tubing string 19 and a minimum amount of rotation of tubing string 19 is required to pull the tubing string 19 oif of permanent tubing extension 23 which passes through packer 16 and has its lower end 24 in fluid communication with fluids flowing from zone 12 through perforations 18 as can be seen by the arrows in FIG. 1. Thus, fluids flowing from zone 12 pass up the tubing string 19.

A conventional one-way ball valve 25 is preferably disposed in extension 23 for preventing backflow of fluids from the upper zone 11 to the lower zone 12. Of course valve 25 is not necessary if the pressure of the zones 11 and 12 is about equal. Tubing string 19 further preferably includes a portion 19a extending upwardly from connector 22 to assist in removing tubing string 19 from well borehole 10 as is well known in the art.

A lower zone cross-over member 26 communicates with the interior of tubing string 19 and preferably extends first outwardly and perpendicular to tubing string 19, then upwardly and parallel thereto as can be seen in FIG. 1. The upper end 27 of member 26 opens into annulus 28 formed between tubing string 19 and casing 14.

A dip tube 29 is in fluid communication with tubing string 19 above the junction of member 26 with string 19 and preferably extends first downwardly and outwardly from tubing string 19, then downwardly substantially parallel to tubing string 19 and portion 19a as can be seen in FIG. 1. The lower end 30 of dip tube 29 is preferably disposed as close as possible to packer 16 so as to prevent corrosive formation fluids from standing on packer 16 and damaging any of the apparatus.

A plurality of sealing bores are preferably formed or otherwise provided at various locations along tubing string 19 between zones 11 and 12. For example, a first sealing bore 31 is preferably formed in tubing string 19 above the point of communication of dip tube 29 with tubing string 19. A second sealing bore 32 is preferably formed in tubing string 19 below sealing bore 31 and between the points of communication of both dip tube 29 and cross-over member 26 with tubing string 19. Finally, a third sealing bore 33 is preferably formed in tubing string 19 below the point of communication of cross-over member 26 with tubing string 19.

A pumping unit 34 is disposed in tubing string 19, the unit 34 including a barrel portion 35. Barrel portion 35 includes a pump extension 36 having a sealing nipple member 42 at its lower end extending down tubing string 19 for reasons to be discussed further hereinbelow. Preferably, both barrel portion 35 and sealing nipple member 42 carry friction cups 37 and 38 or the like, respectively, thereon for engagement with sealing bores 31 and 32, respectively. Thus, the pump barrel portion 35 is held in place in sealing bore 31 by friction cups 37. The length of extension 36 is preferably one integral piece necessitating extensions of various lengths to be screwed or otherwise fastened to barrel portion 35 for carrying out further operations in accordance with the invention, as will be discussed hereinbelow.

Pump extension 36 is perforated, as at aperture 39, for providing fluid communication with dip tube 29. A normally closed port 40 is disposed at the lower end of pump extension 36 having a selectively removable cap 41 or the like thereon.

Barrel portion 35 of pumping unit 34 is open at its upper end and a conventional sucker rod 43 extends therethrough. The upper end 44 of rod 43 extends to conventional pump actuating equipment (not shown) on earth surface 21. At its lower end, rod 43 is coupled to a c nventional pump plunger 45. A conventional travelling ball valve 46, adapted to engage valve seat 47 carried by barrel portion 35, is disposed in barrel portion 35 below plunger 45. A conventional standing ball valve 48, adapted to engage valve seat 49 carried by barrel portion 35, is disposed in barrel portion 35 below ball valve 46. A chamber 50 is formed in barrel portion 35 between valves 46 and 48.

-In operation, packer 16 is installed in well borehole in a manner sealing of zones 11 and 12. Communication is provided between well borehole 10 and zones 11 and 12 through perforations 17 and 18, respectively. A tubing string extension 23 is fixed in packer 16 so that its lower end communicates with formation fluids from zone 12. The tubing string 19 and its associated equipment is latched to the upper end of extension 23 by means of sealing connector 22. The tubing string 19 is thus hung in tension. Preferably, a one-way valve 25 is installed in extension 23 for reasons discussed hereinabove. The pumping unit 34 is installed in tubing string 19 and latched therein as through cups 37 and bore 31. In this first position of the apparatus as set forth in FIG. 1, the well borehole 10 is set up for normal confluent production of formation fluids from zones 11 and 12. In this case, port 40 is plugged by cap 41 and port 39, on pump extension 36, is open.

In operation, as indicated by the arrows in FIG. 1, fluids produced from lower zone 12 enter perforations 18 and go up tubing extension 23 past valve 25,. Since pump extension 36 seals tubing string 19 above member 26, the lower zone formation fluids flow through crossover member 26 and out the upper end 27 thereof into annulus 28. Simultaneously, formation fluids produced from upper zone 11 pass through perforations 17 and down the annulus 28 where the upper zone formation fluids mix with the lower zone formation fluids in annulus 28. Gas interference in the pumping unit 34 is mini mized by venting gas from the formation fluids from both zones 11 and 12 up annulus 28 and out annulus outlet 51.

The mixed formation fluids in annulus 28 enter the lower end 30 of dip tube 29 and pass into tubing string 19. Since tubing string 19 is sealed both above and below port 39, the fluids enter port 39 and flow through extension 36 to the pumping unit 34.

On the up-stroke of sucker rod 43 and plunger 45, travelling valve 46 is closed and fluid is displaced out the to of tubing 20 to suitable on-surface recovery equipment (not shown). Simultaneously, fluids pass standing valve 48 and fill chamber 50. On the downstroke of rod 43 and plunger 45, standing ball valve 48 is closed and travelling valve 46 is open. Fluid in chamber 50 is then displaced into tubing 19 above travelling valve 46. In this manner, commingled production fluids from both upper and lower zones 11 and 12 are recovered simultaneously using essential single-beam pumping equipment. In such case, these steps may be accomplished using the equipment of FIG. 1.

For example, referring now to FIG. 2, a schematic illustration of a portion of the apparatus of FIG. 1 is shown wherein like numerals refer to like parts of FIG. 1. In order to test the upper zone 11, a longer section similar to section 36 is threaded onto or otherwise fastened to barrel portion 35 to the length indicated whereby the cups 38 of sealing nipple member 42 engage the third sealing bore 33 while the cups 7 of barrel portion 35 engage the first sealing bore 31. Port 40 is plugged by cap 41 and aperture 39 is open. Since tubing string 19 is now sealed ofi from fluids passing therethrough by means of cups 38 and bore 33, only formation fluids from the upper zone 11 enter the tubing string 19 through both dip tube 29 and cross-over member 26 into port 39 and into barrel portion 35 of the pumping unit 34 as indicated by the arrows and in the manner discussed hereinabove with respect to the apparatus of FIG. 1.

In like manner, referring now to FIG. 3 wherein like numerals refer to like parts of FIG. 2, only lower zone 12 may be tested. In this feature of my invention, the apparatus is set up in well borehole 10 in the manner discussed hereinabove with respect to FIG. 2. However, cap 41 is removed, thus opening port 40. The aperture 39 on extension 36 is closed (or, alternatively, pump extension 36 is imperforate), so that formation fluids entering crossover member 26 and dip tube 29 cannot enter extension 36. Thus, only fluids from the lower zone 12 can enter the extension 36 into the barrel portion 35 of pumping unit 34 through port 40 as indicated by the arrows in FIG. 3.

In summary, single beam pumping apparatus is disclosed whereby multiple zones traversed by a well borehole may be either confluently produced therefrom or selectively treated. Although the productive capacity of the apparatus is no greater than in dual or tandem beam installations, substantial reduced operating costs lower the economic limit of such zones and increase the total oil production therefrom. Finally a plurality of such zones may be treated in like manner with suitable packers, dip tubes, and cross-over members as required.

I claim as my invention:

1. Apparatus for selectively producing and testing fluids from multiple zones traversed by a well borehole extending into a subterranean earth formation, said zones being in fluid communication with said well borehole with at least one of said zones being lower than another of said zones, the apparatus comprising:

packing means disposed in said well borehole sealing 05 at least one of said zones from another of said zones;

tubing string means extending down said well borehole through said packing means into fluid communication with said lower zone and forming an annulus in said well borehole;

lower zone cross-over means disposed above said packing means in fluid communication with said tubing string means and opening into said annulus above said packing means;

upper zone fluid inlet means in fluid communication with said tubing string means above the junction of said lower zone cross-over means with said tubing string means;

selectively movable pumping means disposed in said tubing string means in a manner adapted to seal off said tubing string means at one point above the junction of said lower zone cross-over means with tubing string means and below the point of fluid communication between said tubing string means and said upper zone fluid inlet means and at another point below the junction of said lower zone cross-over means with said tubing string means; and

said pumping means having a first normally open fluid inlet means therein in selective fluid communication with fluids entering said tubing string means from said upper zone fluid inlet means and a second normally closed fluid inlet means at the lower end thereof in selective fluid communication with fluids entering said tubing string means from said lower zone.

2. The apparatus of claim 1 wherein one-way valve means is disposed in said tubing string means above said packing means and below said junction of said cross-over means with said tubing string means.

3. The apparatus of claim 1 wherein said lower zone cross-over means extends outwardly from its point of junction with said tubing string means, then upwardly and substantially parallel to said tubing string means in the annulus formed between said tubing string means and said well borehole.

4. The apparatus of claim 1 wherein said upper zone fluid inlet means extends outwardly from and substantially downwardly with respect to said tubing string means, the lower end of said fluid inlet means being disposed above but substantially adjacent to said packing means in the annulus formed between said tubing string means and said well borehole.

5. The apparatus of claim 1 wherein said tubing string means includes an extension portion extending through and fixed within said packing means; and

the remainder of said tubing string means being detachably removable from said extension portion and thus from said well borehole.

6. The apparatus of claim 1 wherein said pumping means includes a sucker rod having a pumping unit at the lower end thereof; and

a pump extension extending downwardly in said tubing string means.

7. The apparatus of claim 6 wherein said tubing string means includes a first sealing bore therein above the point of fluid communication of said fluid inlet means with said tubing string means;

a second sealing bore therein between the points of fluid communication of both said fluid inlet means and said cross-over means with said tubing string means;

a third sealing bore therein below the point of fluid communication of said cross-over means with said tubing string means; and

said pumping means including sealing bore engagement means thereon adapted to selectively and simultaneously engage at least two of said sealing bores.

References Cited UNITED STATES PATENTS 3,005,414 10/1961 Coberley 166-105 3,172,469 3/1965 Coberley et al 166-105 JAMES H. LEPPINK, Primary Examiner 

